Avalanche Forecast

Issued: Feb 22nd, 2023 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada rgoddard, Avalanche Canada

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Variable winds have produced wind slabs on all aspects at higher elevations

Use caution as you transition into wind-affected terrain.

Summary

Confidence

Moderate

Avalanche Summary

Tuesday saw an increase in natural avalanche activity that produced avalanches that ranged in size between 1.5 and 4. Our field team reported witnessing several wind slab avalanches up to size 2.5 in extremely steep terrain. Local operators reported wind slab, storm slab, and also persistent and deep persistent slab avalanches. The persistent and deep persistent layers have been relatively quiet since February 16th. This is a good reminder that they could still be reactive in the right location.

On Sunday, a notable skier accidental size 2 storm slab occurred in the backcountry near Terrace. See details in the MIN report.

Snowpack Summary

Variable winds, predominantly and most recently from the northeast, have redistributed up to 40 cm of recent snow at all elevations in exposed areas.

Up to 80 cm now sits over a layer of small surface hoar, facets, and wind-affected surfaces. Below treeline, a new crust could exist up to 1000m.

A layer of facets and a crust from late January can be found down 100 to 200cm. Below this layer, the snowpack is generally well-settled and right-side up.

Weather Summary

Wednesday Night

Clear, no accumulation, winds east northeast 35 km/h and stronger towards the coast, treeline temperatures -20 °C.

Thursday

Sunny, no accumulation, winds northeast 25 to 45 km/h, treeline temperatures -20 to -25 °C.

Friday

Increasing clouds, trace accumulation starting late in the day, winds northwest 35 km/h, treeline temperatures -15 to -20 °C.

Saturday

Cloudy, 10 cm accumulation with more in coastal regions, winds southwest 30km/h gusting to 50, treeline temperatures around -15 ºC and rising.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Keep your guard up at lower elevations. Wind slab formation has been extensive.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
  • Be aware of the potential for large, destructive avalanches due to the presence of deeply buried weak layers.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.

Problems

Wind Slabs

An icon showing Wind Slabs

Variable winds have redistributed 30 to 50 cm of recent new snow into fresh, reactive wind slabs. These slabs will form in a reverse loading pattern and at lower elevations than expected. Wind slabs may be particularly reactive where they overlie a crust.

If an avalanche is triggered it may create enough load to trigger weak layers buried further down in the snowpack. Where this would be most prevalent is the northern part of our region. Keep this in mind when traveling in the backcountry and mitigate this problem by choosing low-consequence terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 23rd, 2023 4:00PM

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